ANALISI RETROSPETTIVA DI DANNO RENALE ACUTO (AKI) IN PAZIENTI (PZ) PORTATORI DI TRAPIANTO D’ORGANO SOLIDO NON RENALE: INCIDENZA E IMPATTO SU MORTALITÀ E FUNZIONE RENALE RESIDUA

[Machine translation] Introduction and purpose of the work Acute kidney injury (AKI) is a frequent complication of patients admitted to intensive care units (ICU) that is often associated with multi-organ involvement and a high incidence of mortality. Despite the increased incidence of chronic kidney disease (CKD) in non-renal organ transplant (NRSOT) recipients related to the use of nephrotoxic immunosuppressive drugs, in particular calcineurin inhibitors, only a few studies have considered the clinical impact of AKI on mortality and progression to CKD in this specific population. The purpose of the present study was to identify the impact of AKI on patient prognosis and progression to CKD in the entire population of NRSOT undergoing dialysis in the period 2001-2010. Materials and methods We retrospectively analyzed all patients admitted to the ICU in the period 2001-2010 who underwent replacement therapy (RRT). The RIFLE and SOFA indices, the ATN_ISS severity index, and the causes of AKI were calculated for all patients at the time the replacement treatment was initiated. The diagnosis of sepsis/septic shock was made in accordance with the criteria of the Society of Critical Care Medicine (Phillip Dellinger R, Carlet J.M. et al. Surviving sepsis campaign guidelines for management of severe sepsis and septic shock. Crit Care Med 2004; 32, 3:858-873). We analyzed: 1) the percentage of NRSOT recipients in the entire population subject to RRT; 2) the percentage of NRSOT patients treated with RRT in the total population of NRSOT and by individual organ transplanted (liver, heart or lung) The patient's prognosis and level of kidney function were reconsidered on the 28th day after admission to the ICU. The impact of sepsis as a cause of AKI and mortality in the entire population and in NRSOT recipients treated with RRT has also been studied. The statistical analysis was carried out using the Hemer-Lemeshow test. Results and discussion In the period 2001-2010, 1833 patients with AKI were treated with RRT (slow hemofiltration lasting 10-12 hours with 0.6-1.3 m2 polysulfone membranes, 50% predilution and 25-30 mL/kg/h as a convective dose target) for a total of 9061 RRT sessions. The characteristics of patients with AKI about to start RRT were: age 66.4±11.5 years, 64.7% male, average creatininemia of 3.8±1.9 mg%, average number of organs involved 3.4±1.38, average ATN_ISS value of 0.738±0.192. Cardiac surgery (23.7%) and sepsis (23.2%) were the main causes of AKI that made it necessary to start RRT sessions (Fig. 1). In the global population affected by AKI, the mortality observed on the 28th day was 64.2%, lower than the expected one calculated with the ATN_ISS score (72%). In the retrospective analysis carried out, the finding of 233 patients receiving NRSOT out of the total population affected by AKI (12.7%) was interesting, a percentage that was up compared to our previous case study. In fact, patients with a liver transplant, 60/229 (26.2%) with a heart transplant, and 22/88 (25%) with a lung transplant, and 22/88 (25%) with a lung transplant, were treated with RRT 151/1335 (11.3%). Analyzing the NRSOT patients according to the RIFLE criteria (Fig. 2), 11.6% were included in the “risk” group, 14.6% in “injury” and 73.8% in “Failure” (three-fold increase in creatinine or reduction in GFR by more than 75%) The main cause of AKI in NRSOT patients was sepsis (43.6%), higher than the total population with AKI (Fig. 3). The overall mortality rate in NRSOT patients treated with RRT was 45.49% (106/233), 43.5% (66/151) for liver transplanted patients, 51.6% (31/60) for heart transplanted patients and 40.9% (9/22) for lung transplanted patients (Fig. 4). In NRSOT patients with AKI associated with sepsis, the incidence of mortality was higher than in patients without sepsis. Furthermore, in septic NRSOT patients, the observed mortality was even higher than the expected mortality calculated with the ATN_ISS score (Fig. 5). These data suggest that the onset of sepsis leads to the development of multi-organ failure and an increase in mortality, as well as making the management of immunosuppressive therapy more complicated. Finally, in the group of surviving NRSOT recipients, the average creatininemia at the end of the observation period was 2.34±0.78 mg% and in particular in the hepatic organ recipients it was 1.97±0.95, in the cardiac organ 2.26±0.72 and in the pulmonary one 2.89±0.83, suggesting a potential progression of the damage from AKI to CKD (Fig. 6). Conclusions Our 10-year retrospective analysis (2001-2010) of critically ill patients treated with RRT in ICU has led to the conclusion: 1) the incidence of AKI appears to have increased in the NRSOT population; 2) the main cause of AKI in the population treated with RRT was sepsis, especially in the NRSOT recipients; 3) the association of AKI and sepsis has resulted in an increase in mortality in the observed global population and in particular in NRSOT recipients; 4) In NRSOT recipients, the onset of AKI has been associated with a worsening of renal function such as to require close, highly specialized nephrological follow-up.